Animal studies have provided compelling evidence in favor of direct anti- atherogenic effects pf JD;-C and apolipoprotein A I (apo A-I). While low HDL-C levels are often associated with an increased risk of coronary artery diseases, human carriers of the Milano mutation in the apo A-I gene are remarkable in that despite extremely low levels of HDL-C, they enjoy freedom from vascular disease and have an ancestral history of longevity. These observations have suggested that the apo A-I/Milano, compared to the wild type apo A-I, apo A-I/wt. While the results of intravenous administration of these rHDL particles have provided evidence of their anti- atherogenic efficacy, the need for repeated intravenous administration remains a practical limitation. Therefore, somatic gene therapy to induce in vivo production of apo A-I offers an alternative approach for utilizing the anti-atherogenic effects of apo A-I. Recently, long-term in vivo expression of transgenes delivered by recombinant adeno-associated virus (rAAV) vectors have been demonstrated. Therefore, in this project we will explore the feasibility and biologic efficacy of gene therapy utilizing rAAV vectors containing the apo A-I/wt and apo A-I/Milano genes in preventing atherosclerosis and pot-injury intimal hyperplasia in the apo E-deficient mouse model. Studies using mouse model of arterial injury will be extended to a large animal model to examine the effects of local gene delivery on the coronary arterial luminal narrowing following balloon overstretch and stent over-inflation injury in swine. The application of gene therapy with apo A- I/wt/apo A-I/Milano gene in the swine vascular injury model may provide the type of preclinical studies needed to demonstrate the feasibility of apo A-I gene therapy in humans. The specific aims are: 1) Analysis of transgene expression in mice following in vivo administration of rAAV vectors encoding apo A-I/wt and apo A-I/Milano genes, 2) Effect of rAAV- mediated transfer of apo A-I/wt and apo A-I/Milano genes on arterial response to carotid injury in apo E-deficient mice, 3) Assessment of feasibility and efficacy of gene transfer using macrophages transduced with rAAV vectors encoding human apo A-I/wt and apo A-I/Milano, and 4) Evaluation of the effects of local rAAV mediated transfer of human apo A- I/wt and apo A-I/Milano genes on coronary arterial luminal narrowing response to balloon-overstretch and stent-overinflation injury in swine.